1. Field of the Invention
The present invention relates to a vandal resistant lock/starter-interlock assembly for buses.
2. Description of the Prior Art
At the end of the work day, buses, especially school buses, are parked outdoors, often in isolated and/or high crime areas. In addition, buses have large doors and many windows. The parking location and bus design make the buses easy targets for vandals and thieves.
As shown in the prior art in FIG. 1, school buses use two latching mechanisms mounted on the door""s exterior to reduce vandalism. The door 114 is closed by the driver from the inside with a latch assembly 110 on the door""s exterior connected to a buzzer or alarm box 113. Starter interlock 120, which prevents the bus from starting when the door is open, is separate from the door latching/alarm assembly. Latch 118 has a sliding latch bolt 116 that extends and connects to an alarm switch 111 within alarm box 113. Breaking the connection between alarm switch 111 and latch bolt 116 activates the alarm.
However, the activation of the alarm does not activate the interlock. A second latching assembly using an ordinary slide bolt 122 connects to a starter-interlock switch within a second box 120 located below alarm box 113. When slide bolt 122 opens, it disconnects from the starter-interlock switch within second box 120. The disconnection activates the starter-interlock system and prevents the bus from being started.
This system requires several external parts attached to the exterior of the door. The assembly of these parts require additional subassembly time and production time. The system also requires the driver to both open the door and unlatch the starter-interlock to activate the starter-interlock.
This prior art assembly requires the alarm to be mounted on the exterior of the skin. Therefore after a break-in, the buzzer alarm can be circumvented. A thief could tape the switch, for example, to keep the switch in its connected position. A vandal can break the alarm itself or remove it from the bus with a object, such as a crow bar.
Because the starter-interlock assembly is separate from the buzzer alarm assembly, if the alarm is vandalized, the starter-interlock can remain intact. This could allow a vandal or thief to start the bus.
The ordinary slide bolt used for the starter-interlock assembly is vulnerable to vandalism. A vandal can easily break the slide bolt with a crow bar or rock. Part of the slide bolt or a rod with a similar diameter, such as a pencil can be left within the starter-interlock assembly connected to the switch.
Therefore, one goal of the invention is to produce a secure alarm and vandal-lock/starter-interlock system that resists vandalism. Another goal of the invention is to produce an alarm/starter-interlock system that can be key locked from the inside. Another goal of the invention is to streamline the assembly of the bus by eliminating a number of parts. Reducing the number of parts can reduce the subassembly time and production time and may possibly reduce the number of overall components and assembly costs.
The invention provides a secure alarm and latch/starter-interlock assembly for a bus door which is vandal resistant. The assembly has a vandal lock with a latch lock adapted to engage a latch bolt and prevent the movement of the latch bolt when locked. The assembly also has means for moving the latch bolt when the vandal lock is unlocked. Both alarm means and starter-interlock means are located within a starter-interlock box. The starter-interlock box has first and second plates and box sides attached to one plate. When unlocked, the alarm means activate an alarm and the starter-interlock means activates a starter-interlock. Typically, the alarm is activated when the latch bolt is moved, usually by moving a door latch. While the starter-interlock can also be activated by moving the latch bolt, it is preferably activated by unlocking the vandal lock.
Additional effects, features and advantages will be apparent in the written description that follows.